Abstract: A molecular recognition element comprising a target molecule-recognizing portion, and a direct electron transfer-type oxidoreductase linked to the target molecule-recognizing portion.

Abstract: A method for measuring a glycated protein in a sample, the method comprising (1) a step of allowing a sample in which a degradation product has been generated from a glycated protein by a protease to react with an oxidoreductase in the presence of an electron mediator to generate a reduced electron mediator; and (2) a step of detecting the reaction state in the step (1) by an electrochemical technique using an interdigitated electrode.

Abstract: A biosensor includes a plurality of electrodes including a working electrode, and a detection layer containing an enzyme for exchanging electrons with the working electrode, a crosslinking agent and an electrically conductive polymer and having a contact area with the working electrode defined by a predetermined area.

Abstract: A mutant cytochrome protein originated from a cytochrome protein having three heme-binding domains, which mutant cytochrome protein lacks the first heme-binding domain and the second heme-binding domain as counted from the N-terminus, is provided. The mutant cytochrome protein may lack a region(s) containing the first and second heme-binding domains.

Abstract: A mutant cytochrome protein originated from a cytochrome protein having three heme-binding domains, which mutant cytochrome protein lacks the first heme-binding domain and the second heme-binding domain as counted from the N-terminus, is provided. The mutant cytochrome protein may lack a region(s) containing the first and second heme-binding domains.

Abstract: By using a mutant glucose oxidase comprising an amino acid sequence in which a residue corresponding to isoleucine at position 489 or arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with an amino acid residue having a reactive functional group in a side chain, and binding an electron acceptor to the mutant glucose oxidase through the amino acid residue having a reactive functional group, an electron acceptor-modified glucose oxidase is obtained.

Abstract: By using a mutant glucose oxidase comprising an amino acid sequence in which a residue corresponding to isoleucine at position 489 or arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with an amino acid residue having a reactive functional group in a side chain, and binding an electron acceptor to the mutant glucose oxidase through the amino acid residue having a reactive functional group, an electron acceptor-modified glucose oxidase is obtained.

Abstract: A measuring method of measuring a concentration of a target ingredient in a sample by using a sensor including an interdigitated array electrode that includes a first electrode and a second electrode, and a reagent layer on the interdigitated array electrode, the measuring method includes: applying a voltage to between the first electrode and the second electrode; measuring a first current value of an electric current flowing between the first electrode and the second electrode; measuring a second current value of the current flowing between the first electrode and the second electrode; calculating the concentration of the target ingredient in the sample, based on a third current value; calculating a correction value, based on the first current value and the second current value; and a step of correcting the concentration of the target ingredient in the sample, based on the correction value.

Abstract: A molecular recognition element comprising a target molecule-recognizing portion, and a direct electron transfer-type oxidoreductase linked to the target molecule-recognizing portion.

Abstract: An enzyme electrode includes an electrode, and a detection layer which contacts the electrode and contains a crosslinking agent, an electrically conductive macromolecule and an enzyme transferring and receiving electrons to and from the electrode and does not contain an electron transfer subunit.

Abstract: The disclosure discloses an enzyme electrode comprising; an electrode comprising a current collector; a monolayer-forming molecule bound to the surface of the current collector; and a glucose dehydrogenase comprising a cytochrome C subunit bound to the monolayer-forming molecule; wherein electrons are transferred between the glucose dehydrogenase and the current collector by oxidation-reduction reaction of the glucose dehydrogenase.

Abstract: By using a mutant glucose oxidase comprising an amino acid sequence in which a residue corresponding to isoleucine at position 489 or arginine at position 335 in the amino acid sequence of SEQ ID NO:1 is substituted with an amino acid residue having a reactive functional group in a side chain, and binding an electron acceptor to the mutant glucose oxidase through the amino acid residue having a reactive functional group, an electron acceptor-modified glucose oxidase is obtained.

Abstract: A method for quantifying a target substance, comprising: bringing a sample containing the target substance into contact with a biosensor which comprises an enzyme electrode containing an oxidoreductase and a counter electrode; measuring a change in the potential difference between the enzyme electrode and the counter electrode due to oxidation reaction of the target substance catalyzed by the oxidoreductase; and calculating the concentration of the target substance based on the change in the potential difference; wherein a potential is applied between the enzyme electrode and the counter electrode before the measurement of the change in the potential difference.

Abstract: The present invention provides a mutant-type glucose dehydrogenase having glucose dehydrogenase activity and having decreased reactivity with xylose, wherein said mutant-type glucose dehydrogenase comprises a mutant-type ?-subunit comprising an amino acid sequence of 520 to 550 amino acids comprising an amino acid sequence of 520 to 550 amino acids comprising SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24 and SEQ ID NO: 25 in this order from N-terminus to C-terminus, except that one or more amino acid residue(s) selected from the group consisting of the glycine at position 10 in SEQ ID NO: 23, the histidine at position 4 in SEQ ID NO: 24, and the asparagine at position 4 in SEQ ID NO: 25 is/are substituted with another/other amino acid(s).

Abstract: A biosensor includes a plurality of electrodes including a working electrode, and a detection layer which is immobilized on the working electrode and contains a crosslinking agent, an electrically conductive macromolecule and an enzyme transferring and receiving electrons to and from the working electrode. The working electrode is in an open system.

Abstract: A method for quantifying a substance, which method includes the steps of: introducing a sample containing a measurement target substance to a biosensor comprising an enzyme electrode comprising an electrode and an oxidoreductase placed on the electrode in a state where direct electron transfer with the electrode occurs, and a counter electrode; applying an AC voltage to the enzyme electrode to carry out impedance measurement; and calculating the substance concentration based on an index obtained by the impedance measurement; is provided.

Abstract: A mutant cytochrome protein originated from a cytochrome protein having three heme-binding domains, which mutant cytochrome protein lacks the first heme-binding domain and the second heme-binding domain as counted from the N-terminus, is provided. The mutant cytochrome protein may lack a region(s) containing the first and second heme-binding domains.

Abstract: A method for measuring a glycated protein in a sample, the method comprising (1) a step of allowing a sample in which a degradation product has been generated from a glycated protein by a protease to react with an oxidoreductase in the presence of an electron mediator to generate a reduced electron mediator; and (2) a step of detecting the reaction state in the step (1) by an electrochemical technique using an interdigitated electrode.

Abstract: The disclosure discloses an enzyme electrode comprising; an electrode comprising a current collector; a monolayer-forming molecule bound to the surface of the current collector; and a glucose dehydrogenase comprising a cytochrome C subunit bound to the monolayer-forming molecule; wherein electrons are transferred between the glucose dehydrogenase and the current collector by oxidation-reduction reaction of the glucose dehydrogenase.

Abstract: The present invention provides a mutant-type glucose dehydrogenase having glucose dehydrogenase activity and having decreased reactivity with xylose, wherein said mutant-type glucose dehydrogenase comprises a mutant-type ?-subunit comprising an amino acid sequence of 520 to 550 amino acids comprising an amino acid sequence of 520 to 550 amino acids comprising SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24 and SEQ ID NO: 25 in this order from N-terminus to C-terminus, except that one or more amino acid residue(s) selected from the group consisting of the glycine at position 10 in SEQ ID NO: 23, the histidine at position 4 in SEQ ID NO: 24, and the asparagine at position 4 in SEQ ID NO: 25 is/are substituted with another/other amino acid(s).